The described subject matter relates to turbine engines, and more particularly, to wear interface surfaces for use in turbine engines.
Turbine engines such as those used for aircraft have journal bearings in multiple locations, including those used to support rotating elements disposed in shaft bearing assemblies and fan drive gear systems. Interface surfaces of the journal bearings and the rotating elements they support must have sufficient hardness and resiliency to resist wear even under extreme combinations of pressure and velocity. One common wear interface surface for elements rotating about aircraft journal bearings is a magnetron-sputtered copper-lead alloy with a specialized microstructure. The manufacturing process of this alloy is complex and expensive, requiring specialized equipment.
Similar properties have not been previously available in silver-based coatings. Silver has been used previously to provide a low-friction surface for various alloys, but standard silver coatings have a relatively short useful life due to limited hardness and resilience properties. Thus they have not traditionally been useful for high performance applications requiring long service life and maintenance intervals over a wide variety of extreme operating conditions.